较低的表面 meaning in Chinese

underneath

This special membrane is a porous hydrophobic membrane , which means that water vapor can pass through it , but drops of water cannot . by passing hot seawater through one side of the membrane , only the water vapor generated from the seawater passes through , the water vapor is then cooled by the cool water on the other side of the membrane , forming water drops , resulting in freshwater
在膜蒸馏过程中，被加热的咸水产生水蒸汽，水蒸汽透过膜，膜的特点是允许蒸汽透过而液态水却不能通过，透过的水蒸汽遇到温度较低的表面后冷凝，冷凝的水滴由于膜的特殊性不能透过膜而返回，将其进行收集便得到淡水。